Not Applicable
The field of this invention is Radio Frequency Indentification (RFID) and, more specifically a compact, RF-powered voltage pump for providing a programming voltage to an EEPROM in an IC-implemented RFID.
Briefly, this invention employs a simple semiconductor circuit on a radio frequency transponder integrated circuit (IC) to power the logic functions and to generate the required EEPROM programming voltage (VPP). VPP is used to force the tunneling of electrons from an xe2x80x9cactive regionxe2x80x9d to a floating-gate region of the EEPROM memory cell transistor, that is, to write to the EEPROM. The inventive semiconductor circuit takes advantage of the fact that a close near field coupling can generate voltages far exceeding 10-20 volts. The inventive circuit may therefore provide the necessary programming voltage of 10-17 volts replacing traditional charge pump voltage-multiplier circuits of the prior art. EEPROMs are usually used as part of a miniaturized, self-contained read/write capable radio frequency transponder IC, where the transponder is implemented as a single semiconductor integrated circuit, and on which a high voltage generator is used to deliver the necessary EEPROM programming voltage to enable the transponder""s EEPROM read/write functions.
This invention recognizes the fact that a traditional on chip charge pump voltage-multiplier takes up about 15% of an RFID transponder silicon chip""s real estate and is typically used less than 1% of the time. In the case of a voltage generator powered by the near field coupling, also called xe2x80x9cRF powered voltage generatorxe2x80x9d, the same circuit takes less than 2% of the chip""s silicon real estate to perform the same functions. This 13% silicon real estate reduction is accomplished by switching from a charge pump voltage-multiplier to an RF powered voltage pump to generate the EEPROM programming voltages.